Assembly of thermally reduced graphene oxide nanostructures by alternating current dielectrophoresis as hydrogen-gas sensors

Abstract

Chemo-resistive hydrogen-gas sensors based on thermally reduced graphene oxide (rGO) have been fabricated on a micro-hotplate by positive ac dielectrophoresis (DEP). The optimized DEP parameters for manipulating rGO nanostructures into Au electrodes for hydrogen sensing are: applied frequency = 1 MHz, peak-to-peak voltage = 5V, and DEP time = 30 s. The device exhibits good sensitivity (similar to 6%) with fast response time (similar to 11 s) and recovery time (similar to 36 s) for 200 ppm hydrogen gas at room temperature. This result indicates that the DEP process has great potential for assembling rGO for hydrogen-gas sensor in many industrial and scientific applications. (C) 2013 AIP Publishing LLC.